The following is a summary of “Prognostic accuracy of ultrasound measures of fetal head descent to predict outcome of operative vaginal birth: a comparative systematic review and meta-analysis,” published in the JULY 2023 issue of Obstetrics and Gynecology by Skinner, et al.

For a study, researchers sought to compare the effectiveness of intrapartum transperineal ultrasound measures in predicting complicated or failed operative vaginal birth and to assess their prognostic accuracy.

A systematic search was conducted in Medline, Embase, CINAHL, and Scopus from inception to June 10, 2022. Studies that assessed intrapartum transperineal ultrasound measures before operative vaginal birth to predict procedure outcomes were included. The considered variables included progression angle, head direction, head-perineum distance, head-symphysis distance, midline angle, and/or progression distance. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Bivariate meta-analysis combined sensitivities and specificities into summary receiver operating characteristic curves for each intrapartum transperineal ultrasound measure. Subgroup analyses were performed to compare measures taken at rest versus with pushing and to predict failed versus complicated operative vaginal birth.

In the study, a total of 16 studies involving 2,848 women who underwent attempted operative vaginal birth were included. The prognostic accuracy of intrapartum transperineal ultrasound measures taken at rest to predict failed or complicated operative vaginal birth was as follows: high for angle of progression (area under the receiver operating characteristic curve, 0.891; 9 studies) and progression distance (area under the receiver operating characteristic curve, 0.901; 3 studies), moderate for head direction (area under the receiver operating characteristic curve, 0.791; 6 studies) and head-perineum distance (area under the receiver operating characteristic curve, 0.747; 8 studies), and fair for midline angle (area under the receiver operating characteristic curve, 0.642; 4 studies). 

However, there was no study with sufficient data to assess head-symphysis distance. According to subgroup analysis, measurements taken while pushing tended to have a higher area under the receiver operating characteristic curve for the midline angle (0.903; 3 studies), progression distance (0.930; 2 studies), and angle of progression (0.927; 4 studies), with similar areas for head direction (0.802; 4 studies). On the other hand, the prediction of failed versus complicated operative vaginal birth tended to be less accurate for the angle of progression (0.837 [4 studies] vs 0.907 [6 studies]) and head direction (0.745 [3 studies] vs 0.810 [5 studies]), primarily due to lower specificity. However, it was more accurate for head-perineum distance (0.812 [6 studies] vs 0.687 [2 studies]).

The angle of progression, progression distance, and midline angle measured with pushing demonstrated the highest prognostic accuracy in predicting complicated or failed operative vaginal birth. Overall, the measurements seemed to perform better when taken with pushing rather than at rest.

Source: ajog.org/article/S0002-9378(22)02187-1/fulltext